1. Field of the Invention
This invention relates to rail cars adapted for transporting automobiles. More specifically, this invention relates to sliding end closure panels for a rail car adapted for transporting automobiles.
2. Description of the Prior Art
For the security and protection of the automobiles, rail cars are provided with sidewalls, roof, and end doors. Typically, the rail cars are designed to have a bed and either one or two intermediate decks supported above the bed for holding the automobiles loaded thereon. The automobiles are driven from platforms at the end of the rail car onto either the bed or a deck for loading.
The height of rail cars for carrying automobiles is often critical. Where it is desirable to carry three levels of passenger cars or two levels of vans or trucks, it is essential to raise the roof of the rail car as far as possible. Due to the fact that rail cars must pass through underpasses and tunnels, the height of the roof is limited. The roof can, however, be higher if the edges between the sidewalls and the roof are sloped. The roof is then similar to a gambrel roof on a house except there is no ridge but a flat span between the curbed sides. Indeed, they almost always are sloped. This enables the rail cars to pass through tunnels with arched ceilings even though the highest point on the rail car exceeds the height of the base of the arch.
A number of end enclosure designs are known for rail cars of the type being discussed. U.S. Pat. No. 3,911,831 discloses a folding end door comprised of hinged panels. The panels of the door fold in overlying relationship to one another in the open position and unfold across the end of the rail car in the closed position. In the open position the folded panels are positioned inside the rail car adjacent the sidewalls resulting in a reduced loading area. Moreover, in the closed position the panels do not extend across the gambrel roof of the rail car to prevent access into the rail car.
Other types of end enclosures usually comprise doors that slide from the closed position to a position along the inside of the sidewalls. The doors are hung from a track member that is positioned along the edge of one of the decks. A space is provided between the side of the deck and the sidewalls at the end of the rail car so that a portion of the track is spaced and substantially parallel to the sidewalls. Thus, the doors can be moved along the track to a position along the inside of the sidewalls to enable access to the interior of the rail car. A suitable guide track or rail is usually provided adjacent the bottom edges of the doors. The guide track does not hinder the operation of the door and provides security by restricting the outward movement of the lower end of the door. Thus, access may not be gained to the interior of the rail car by pulling out the bottom edges of the doors away from the opening. A door of the type being described is disclosed in more detail in U.S. Pat. No. 4,437,410.
Since the edges where the roof and sidewalls are joined are sloped, it is not possible to extend the doors upwardly to completely fill the gable space and still slide the doors back along the sidewalls. The higher portion of the door would interfere with the sloped portions of the roof. Numerous schemes have been devised to attempt to fill the gable space. Some doors are built with top portions bent inwardly so that they will not interfere with the sloped portion of the roof (see U.S. Pat. No. 4,437,410). In some cases, complicated folding panels close the gable portion of the space (see U.S. Pat. No. 4,265,183). In yet other cases, the gable space is simply left open (see U.S. Pat. No. 3,996,860).
One manner of solving the above problem, as suggested by U.S. Pat. No. 3,995,563, is to use an end closure comprising two sliding doors which move between closed and open positions. Upon opening of the doors, each door moves into an open space on the outer side of the rail car through a vertical opening in the sidewall. Each door includes an arcuate laterally outer portion and a straight laterally inner portion attached tangent to the laterally inner edge of the arcuate portion. Each door is supported to ride on an arcuate track having the same radius of curvature as the arcuate portion of the door. The door is supported on the track by rollers attached solely to the arcuate portion.
The opening in the sidewall allows the door to cover the gable portion of the space. However, the opening in the sidewall provides an undesirable degree of access to the interior of the rail car from outside, placing the contents of the rail car in jeopardy of damage from vandalism and other outside forces. In addition, support of the door on rollers only on the arcuate portion results in a relatively weak support of the laterally inward portions of the doors.
The extension of the door through the sidewall presents problems with respect to support of the required ladder at the end of the car. In the prior art, the ladder is supported by a brace beam connected to its top end. Because the door is taller than the height of the brace beam, a slot is cut in the door to allow it to open. This slot weakens the laterally outward upper corner of the door, which may be bent back to gain access to the interior of the car.
It is an object of the present invention to provide a rail car with shaped roof and doors that fill the entire opening of the open end of the rail car and can be easily moved to a stowed position along the sidewall. It is a further object of the invention to eliminate a permanent ladder panel positioned on the corner of the rail car. It is yet another object of the present invention to provide rail car doors that can be readily applied to deck structures of various widths. Another object of the present invention is to provide rail car doors that are economical to assemble, lower in weight and are simple to operate under all loading and unloading conditions.